<h2>Your Cart</h2>
<table>
<%= render(cart.line_items) %>
<tr class="total_line">
<td colspan="2">Total</td>
<td class="total_cell"><%= number_to_currency(cart.total_price) %></td>
</tr>
</table>
<%= button_to "结帐", new_order_path, method: :get %>
 <%= button_to '清空购物车', cart, method: :delete,data: { confirm: 'Are you sure?' } %>